refactor: make refund_params mandatory

[Janislav]

Pull Request

Closes: PRO-1702

Checklist

Please conduct a thorough self-review before opening the PR.

• I am confident that the code works.
• I have written sufficient tests.
• I have written and tested required migrations.
• I have updated documentation where appropriate.

Summary

Please include a succinct description of the purpose and content of the PR. What problem does it solve, and how? Link issues, discussions, other PRs, and anything else that will help the reviewer.

[codecov]

Codecov Report

Attention: Patch coverage is 30.43478% with 32 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
engine/src/witness/evm/vault.rs	0%	24 Missing ⚠️
state-chain/pallets/cf-ingress-egress/src/lib.rs	70%	3 Missing ⚠️
engine/src/witness/arb.rs	0%	2 Missing ⚠️
engine/src/witness/eth.rs	0%	2 Missing ⚠️
...te-chain/runtime/src/chainflip/solana_elections.rs	0%	1 Missing ⚠️

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